I've recently bought a new netbook. A netbook is a extra small lightweight laptop computer, with screens between 7" and 12". They have low spec processor so are not usually a replacement for traditional computers (although that depends upon what you want out of them), but with good network connectivity and extremely portable.

Choice of operating system - Windows XP vs. Linux

The first thing to notice is that there is no mention of Windows Vista. None of the netbooks I have seen have had Windows Vista as an option. There is good reason for this, Windows Vista is bad enough on a full spec laptop (see review of Windows Vista compared with Windows XP), even the more expensive netbooks only just meet the minimum specifications for running Windows Vista and none that I have seen meet the recommended specification (e.g. 2GB memory and high performance graphics card).

In addition the main benefit I can see in having Windows XP is that it will be familiar to many people. Unfortunately that is missing so much of what is on offer on the Linux based system. For example in the case of the Linux operating system provided on the Eee PC it is far easier to use and to keep running than Windows XP.

The following are advantages to the Linux version:

Cost - Linux based systems tend to be cheaper on identical hardware

Performance - Linux is generally much leaner than Windows XP

Easy to use - The linux operating system has been made very easy to use, in many ways much more user friendly than Windows XP

Designed for the netbook - Linux allows for extensive customization and many of the netbook manufacturers have used that to provide an interface more suited to a netbook

Safer and less prone to viruses, trojans and spyware - There are no real Linux viruses in the wild so there is no need to run anti-virus software. This saves both money and the precious computer resources that can be used elsewhere. The problems that have plagued Windows Internet Explorer in launching hundreds of browser windows at startup are not a problem on Linux

More stable - in my own experience I have found Linux to be more stable (perhaps related to above).

Free open source software - the freedom to modify or improve as you wish

Development of the open source software helps the whole community rather than just funding the Bill Gates retirement fund

Choice of Netbook: Screen and keyboard size and capability

I had already decided that the netbooks with 7 inch screens were not for me. Although these are the cheapest available (less than £200) I wanted something with a decent sized screen and these netbooks have too little storage for me.
The next size is 9 inch (actually normally 8.9 inch for some reason). I was quite happy with the screen size, but I had a look at a number of these in shops and decided that they keyboard was too small. I am a touch-typist and I have quite large hands and typing on these tiny keyboards produced almost as many errors as they did correct key-presses. I therefore looked at the next size up which is 10 inches.
Actually there is one model available with a 9 inch screen embedded in a 10 inch equivalent netbook. This is the Asus Eee PC 904, this has the benefit of being slightly cheaper (but only slightly) but with the advantage of the larger keyboard. Getting hold of one (especially with Linux) is nigh on impossible and it was better to pay slightly more for a full 10 inch anyway.
Some manufacturers also provide 12 inch netbooks. These are starting to get a bit big to lug around (more like a normal laptop) and quite expensive for a small portable laptop, so I did not really look at these.
The next criteria I looked at was storage. I specifically say storage rather than hard disk drive as many of these do not have hard disk drives (HDD) instead using solid state storage / flash memory based storage (like having a USB memory stick built-in, instead of a hard disk drive). These start from 4GB SSD on the smallest devices, but go up to 160GB Hard Disk Drives on some models.
The storage can normally be added to using a USB memory stick, SD cards or an external Hard Disk Drive (some models e.g. the miniBook supplied by Maplin do not support external Hard Disk Drives). Some also include web based storage (perhaps at additional cost).
The SSD disks have been 4GB and 80GB capacity (although this is increasing on new models). This is much less than a typical PC / laptop. If the device is being used just for web access and some documents then the 4GB can be sufficient.
I want to be able to use the netbook as a backup for my photos when travelling and for holding my entire MP3 collection as a mobile music player. This is not possible with the smaller capacity SSD netbooks. In the end my decision came down to either a 40GB SSD or a 160GB HDD which were approximately the same cost. The SSD has advantages as well as it is likely to be faster and less likely to be damaged / lose data if dropped when in use. After an initial dilemma I decided that I liked the idea of having extra storage so went for the 160GB hard disk drive version.

Shopping for a Linux netbook on the high street

I set about looking at what is available at the high street shops.
The first netbooks (Asus EeePC with 7 inch screen) came out on Linux and they are widely available. The one thing I did find was few of the high street stores sell Linux models with screens larger than 9 inches. Generally they only sell the cheaper range Linux netbooks.
I can see why Linux is popular on the smaller sizes as it has a significant price advantage, but that is not the only reason for choosing Linux. Unfortunately this means that people may well be missing out on the advantages of Linux on the high-end netbooks.
Here is a list of a few of the high-street retailers that sell netbooks:

Maplin Electronics - low cost Linux only (does not sell Windows XP) - These are very basic costing less than £150, but not as good as the other netbooks.

Argos - does not sell Linux netbooks.

Shopping for a Linux netbook on the Internet

Giving up on the high street I looked on the web. There are a number of suppliers available, but in the end it came back to 4 suppliers.
Dell provide a number of different computers (including laptops and desktops with linux pre-installed). They had a number of options for the 9 inch and 12 inch Inspiron mini laptops, but not the 10 inch which ruled them out.
I then limited myself to the Asus Eee PC 1000 (looking at both the HDD and SSD options), which came down to 3 suppliers with similar prices all of which I have used in the past.

Misco had the 160GB HDD version. But for some reason the Linux version was more expensive than the Windows version

At first I was put off my Misco charging more for Linux rather than Windows XP. With no license to pay to Microsoft it should be cheaper for Linux (it seams to vary but many models are about £25 cheaper with Linux). Thinking about it, the Linux operating system is very much tailored for the device and far superior so I don't actually mind I'd still buy linux even if it is more expensive, although it does mean it's cheaper to go to a different supplier.

Making the purchase

In the end I bought from Expansys as I wanted the 160GB version and that had a slightly better price at the time. The price of these does seam to fluctuate so it may be worth trying all the above suppliers to see which is offering the best price at the time - or try one of the advertisers on this site :-)
I now have the Eee PC and I think it's great. I'm very impressed by how professional it looks and how easy it is to use. I haven't had chance to really put it through it's paces - really it's for my Birthday which isn't until tomorrow anyway ;-)
I'll be writing lots more on Linux and the Eee PC in the future on the Penguin Tutor Linux Blog and the Asus Eee PC Linux Netbook Blog.